Thanks CCleaner Team for the update. I understand the challenges, but from a user side it is also weird, when your 64bit installation of an app gets overwritten by a 32bit installation without any notice. Especially if you don't have an a eye on this all the time.
Maybe as some food for thought: You could check the PE-Header of the executable for the IMAGE_FILE_MACHINE_AMD64 in the "Machine Type" section to recognize if the installed binary like "vlc.exe" is a 64bit executable or 32bit executable. Another option would be to ask the user actively if he would prefer the 64bit or 32bit release.
But please see that just as some personal ideas.
BTW: I really like CCleaner and I am using it already for years. Thanks for the good work.